Calibration of Pyrometric Cones

Pyrometric cones produced by the Standard Pyrometric Cone Company (now known as The Edward Orton, Jr., Ceramic Foundation) were calibrated at the National Bureau of Standards in 1926. Cones available from the 1926 calibration were recalibrated, and new working standards were obtained by calibrating specimens of present production from the Orton Foundation. Heating rates of 150° and 60°C. per hour were used in determining the end points of a series of large cones, whereas a rate of 300°C. per hour was employed for the small cones through cone 12. The pyrometric cone equivalent (P.C.E.) series was calibrated and extended down to cone 12
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POTASH–SODA–LIME FELDSPAR EUTECTIC STUDY*

An investigation was made of the fusion behavior of the potash feldspar, soda feldspar, and soda-lime feldspar system, all materials being of commercial grade. The potash feldspar had a pyrometric cone equivalent of cone 9½, the soda feldspar, cone 6½, and the soda-lime feldspar deformed at cone 11½. Mixtures varying according to the triaxial diagram were made in the form of pyrometric cones. These were fired in groups along with standard Orton cones. The 30% commercial potash feldspar-70% commercial soda feldspar mixture reached 6 o'clock deformation when standard Orton cone 6 showed 2 o'clock deformation. The mixture of 62½% commercial potash feldspar with 37½% soda-lime feldspar reached 6 o'clock deformation when cone 7 showed 1 o'clock deformation, the deformation of the cone 9½ potash feldspar being reduced 3 cones by the addition of the proper percentage of the cone 11½ soda-lime feldspar. There was an increase in deformation temperatures (no indication of eutectic) in the plagioclase series, soda feldspar to soda-lime feldspar. The mixture of 30% commercial potash feldspar, 60% commercial soda feldspar, 10% soda-lime feldspar showed 6 o'clock deformation when cone 6 showed 1 o'clock deformation, this being the lowest temperature at which any member of the system showed 6 o'clock deformation.     

THERMAL AND MOISTURE EXPANSION OF KAOLINS AND BODIES FIRED TO DIFFERENT TEMPERATURES*

Thermal-expansion and moisture-expansion determinations were made on four kaolins of the Georgia, Florida, North Carolina, and English types alone and on typical semivitreous, hotel china, and electrical porcelain bodies embodying each of these kaolins after being fired at cones 6, 9, and 11. The Georgia and Florida kaolins and bodies showed surprisingly similar expansion characteristics. The general order of decreasing thermal expansion and increasing moisture expansion of the kaolins at all three firing treatments was Georgia, Florida, North Carolina, and English china. The semivitreous bodies at cones 6 and 9 showed the same order of expansion as the kaolins alone, but at cone 11 the thermal expansion of the English china clay body was the highest and the North Carolina kaolin body next in order. Moisture expansion of the bodies at cone 11 was found to be a function of the absorption, regardless of the kaolin used with no expansion obtaining at zero absorption. Mixtures of clay, flint, and feldspar, given an autoclave treatment after being fired to cones 6 and 9, showed that feldspar additions increased moisture expansion. When these mixtures were dehydrated at different temperatures, the data obtained were insufficient to confirm any theory on the nature of moisture expansion in a porous ceramic body.     

MINERALS AND MINERAL RELATIONSHIPS OF THE CLAY MINERALS *

The invitation to be the Edward Orton, Jr., Fellow Lecturer of the American Ceramic Society for 1945 is a very great honor and a privilege which one interested in the mineralogy of clays must heartily appreciate. Dr. Orton was a geologist as well as a founder of this Society, and no doubt in issuing this invitation you had in mind the maintenance of this historic relationship. Those of us who follow him cannot add to that relationship, but I hope that I can help to foster it. Perhaps not all geologists know of this common ground between ceramics and geology as you do, and no doubt you would have me remind my geologic colleagues of this and of the mutual contributions which its maintenance entails. Another common bond of interest is that ceramists have made use of mineralogic and petrographic techniques to an extent not matched in any other applied science. In particular, they have utilized the petrographic microscope, and ceramists and mineralogists alike have found in X rays a wonderful new method of research. Clays, the subject of this lecture, should provide a common meeting ground and one which no doubt would win the hearty approval of Dr. Orton.     

THERMAL AND MOISTURE EXPANSION OF BALL CLAYS AND BODIES FIRED TO DIFFERENT TEMPERATURES*

Thermal and moisture expansion determinations were made on ten ball clays of the Kentucky, Tennessee, and English types alone and on typical semivitreous and vitreous bodies in which each of these ball clays was incorporated. The clays and bodies were fired at cones 6, 9, and 11. The data indicate that the ball clays fall into five distinct groups. Although none of the clays showed a direct relation between its expansion and that of the bodies in which it was incorporated, a majority possessed characteristics sufficiently similar to permit their classification into groups in which the behavior of the clays alone is indicative of their influence on the bodies. When several ball clays were jointly incorporated into bodies, they showed additive thermal and moisture expansion values.     

THE EFFECT OF FIRING TEMPERATURE ON THE DIELECTRIC STRENGTH OF PORCELAIN1

An electrical porcelain body (H and G A1 English china clay, 30%; Tennessee ball clay No. 7, 20%; Buckingham feldspar, 30%; Ottawa flint, 20%) was fired to various cone temperatures and the puncture voltages were determined. The mean values in kilovolts per quarter-inch thickness were cone 7, 37; cone 8, 51; cone 9, 60; cone 10, 63; cone 11, 61; cone 12, 64. The probable error of the mean in each case is approximately ± 1 kilovolt per quarter inch. The differences of the means between cones 9 and 12 were shown statistically to be without significance. Other conditions remaining identical, it was shown that the most uniform body resulted when fired to cone 9.     

INCREASE IN REFRACTORINESS IN CERAMIC BODIES IN INTERRUPTED HEAT TREATMENT1

The increase in refractoriness referred to here is usually termed freezing. The study was undertaken to overcome the tendency of pyrometric cones to set or freeze when subjected to prolonged heat treatment when the temperature is more or less fluctuating. The work includes a study of the freezing tendency of some natural clays, of several pottery bodies, and of pyrometric cones. A body was developed that does not freeze under the treatment that produces the phenomenon in the other materials tested but the cause is not established.     

COLLOID CHEMISTRY IN CERAMICS*

Mr. Chairman, Fellows of The American Ceramic Society, Members, and guests! I consider it a great honor to have been invited to deliver before this gathering the Edward Orton, Jr., Memorial Lecture for 1941. That your choice has fallen on me, neither a ceramist by profession nor a specialized ceramic chemist or physicist, makes me even more proud, and I therefore want to thank you from the bottom of my heart. I come here not to offer you a lecture on recent developments in ceramics, a topic which undoubtedly will be handled in the course of your Meeting by more competent men, but to lay before you in simple form a few fundamental colloid chemical and physical concepts which have a direct bearing on basic problems in ceramics. This consideration of why and where colloid chemical reasoning and research have become a science indispensable for progressive developments in ceramics is the greatest tribute to the memory of Edward Orton, Jr., who pioneered in the United States in the importance of scientific research in ceramics.     

ORIGINAL PAPERS THE BONDING EFFECT OF BALL CLAYS IN FIRED BODIES1

Seven American and fourteen English ball clays were compared in regard to bonding effect, (a) after burning, in a composition containing no fluxes, at cones 5, 8, 10 and 12; (b) in a semi-porcelain body burned to cone 8; and (c) in a vitreous china body burned to cone 11. The English clays developed greater strength in the absence of fluxes. The semi-porcelain and vitreous china bodies containing the imported clays were in general of greater strength than those bodies in which the domestic clays were used, but most of the bodies containing American clays were of good transverse strength.     

NOTE ON LADLE BRICK1

Review of Literature on Ladle Brick. —(1) American ladle in which it is stated no chemical reactions occur; (2) English ladle in which four or five chemical reactions occur simultaneously. Fusion Point of Ladle Brick ranging from cones 17 to 30 depending on behavior of clay at temperatures below the fusion point. Process of Manufacture. —Two processes, namely dry press and stiff-mud with preference for dry press. Modification of standard refractories is suggested.     

VARIATIONS IN PYROMETRIC CONE EQUIVALENTS OF SILICA CEMENTS AND FIRE CLAYS1

In order to determine what variations might occur due to the method of preparing the sample for the pyrometric cone equivalent test a series of 100 silica cements and five fire clays were tested using the cement “as received,” ground to pass a 65-mesh Tyler screen, and after calcining a t 1400°C grinding to pass a 65-mesh Tyler screen. The pyrometric cone equivalent values were obtained by two operators, the cones being made by one operator. It was found that testing of silica cements “as received” gave closer checks than ground samples. The grinding of the sample lowers the pyrometric cone equivalent 1^1/2to 2 cones in general.     

THE DIELECTRIC STRENGTH OF PORCELAIN: THE INFLUENCE OF POROSITY*

This work utilized the samples used by Monack, Shardlow, and Warnsley in previous experiments.¹ Between cones 7 and 10, the dielectric strength was found to be inversely proportional to the per cent apparent porosity. Between cones 10 and 15 the dielectric strength increased gradually while the apparent porosity remained essentially zero. No relation existed between dielectric strength and total porosity (open and closed pores). Overfiring does not seem to decrease the dielectric strength unless a definite vesicular structure is developed.     

Parameter set selection for dynamic systems under uncertainty via dynamic optimization and hierarchical clustering

It is common that only a subset of the parameters of models can be accurately estimated. One approach for identifying a subset of parameters for estimation is to perform clustering of the parameters into groups based upon their sensitivity vectors. However, this has the drawback that uncertainty cannot be directly incorporated into the procedure as the sensitivity vectors are based upon the nominal values of the parameters. This article addresses this drawback by presenting a parameter set selection technique that can take uncertainty in the parameter space into account. This is achieved by defining sensitivity cones, where a sensitivity cone includes all sensitivity vectors of a parameter for different values, resulting from the uncertainty, in the parameter space. Parameter clustering can then be performed based upon the angles between the sensitivity cones, instead of the angle between sensitivity vectors. The presented technique is applied to two case studies. © 2013 American Institute of Chemical Engineers AIChE J, 60: 181–192, 2014     

The separation of coal fines using flowing-film gravity concentration

This paper reviews the results of a broadly based investigation into the possible merits of treating coal fines using flowing-film gravity separators such as Reichert cones, trays and spirals. The work was carried out in the test facilities maintained by Mineral Deposits Limited (MDL) both within Australia and in several overseas locations. In the initial phase, the cost of the work was borne by MDL, but funding for the second phase, which had wider terms of reference, was supplied by a grant from the National Energy Research, Development and Demonstration Council (NERDDC). The project is expected to continue until mid-1984, but the assessments of the tray and spiral separators are complete and form the main subject of this paper.     

THE DIELECTRIC STRENGTH OF PORCELAIN: THE INFLUENCE OF FIRING TEMPERATURE1

This paper completes the work previously reported by Monack and Shardlow² The additional puncture voltages in kilovolts per quarter-inch thickness were cone 13, 60; cone 14, 69.5; cone 15, 67. The puncture voltage increased gradually between cones 9 and 15. Other conditions remaining identical, it was shown that the most uniform body resulted when tired to cone 9.     

Traffic cones from recycled vinyl

Injection molded cones have been successfully produced using a high content of recycled wire and cable fluff. The cone meets all general specifications. Its properties are comparable to a conventional plastisol traffic cone. This work demonstrates the feasibility of using recycled wire and cable fluff in injection molding applications.     

Electronic transport properties of phosphorene/graphene(silicene/germanene) bilayer heterostructures: A first-principles exploration

Recently, new researches on van der Waals (vdW) two-dimensional bilayer heterostructures have been carried out owing to their unique properties different from single-layer materials. Herein, three types of bilayer heterostructures, phosphorene/graphene, phosphorene/silicene and phosphorene/germanene are constructed and their electronic transport properties are calculated based on the first-principle method. The results show that their I-V curves are totally different that the phosphorene/graphene devices have higher electron transmission probability, resulting in higher current values. Furthermore, we calculate their band structures to explore the internal mechanism of current difference. The graphene-like Dirac cones are found in the bilayer phosphorene/graphene heterostructures. However, the positions of their Dirac cones in the Brillouin zone are markedly different from that of graphene. But when the silicene or germanene is combined with the phosphorene together, the Dirac cones of the silicene or germanene disappear, instead, there are band gaps of about 0.2?eV around the Fermi level. Our results suggest that the Dirac cone can be mainly retained by the weak hybridization between monolayer phosphorus and 2D Dirac materials. Due to the existence of the Dirac cone, the overlap between the source and drain electrodes increases, which leads to a larger current value. This discovery of the Dirac cones in the bilayer heterostructures is applicable in designing Dirac materials and understanding their electronic transport properties.     

Shape influences on the packing density of frustums

The shape of a frustum is a bivariate function of aspect ratio (w) and base radii ratio (c). To investigate the shape influences on the packing density of frustums, random packings of cones (c = 0), truncated cones and cylinders (c = 1) with various heights and diameters are studied through numerical simulations. An improved relaxation algorithm with assembly sphere models for non-spherical particles is applied in the numerical simulations, and the randomness of the packings of the frustums considered is verified. Base on the simulation results, the relationship between the packing density and shape parameters is illustrated, and an empirical formula is proposed to reflect the correlation. It shows that, for the particles having the same w, truncated cones can be packed denser than cones, but looser than cylinders. The packing density of truncated cones first increases and then decreases with the growth of w, while the packing density increases monotonically with the increase of c. No obvious peak is found on the curve of packing density versus c for the random packing of truncated cones, which is different from the reported results for ordered packing where a peak was identified. Furthermore, we observe that the packing density of truncated cones is a linear superposition of the c effect on w effect, and the effects of c and w on the packing density can be treated independently. The optimal aspect ratios of truncated cones, which give the highest packing densities, are all around 0.8. The highest packing densities of cylinders and cones are also the upper and lower bound of the random packing density of truncated cones.     

Response of polycarbonate,poly(methylmethacrylate), and epoxy resins to dynamic contact loading I. Experimental results

Measurements of the resistance force to a wide range of contact loadings have been performed on poly(methylmethacrylate), polycarbonate, and epoxy specimens. Rigid spherical indenters of 4.5, 9, and 18 mm diameter, as well as cones of various apex angles, were driven into thick specimens at constant velocity over the range 0.005 to 150000 mm/min. The objective of this study was to develop a data base useful for the understanding and analysis of the phenomena involved when polymeric solids are impacted by small hard bodies. Spheres and cones were used because these symmetrical shapes offer the best chance for analysis in terms of viscoelastic extensions of the classical Hertz elastic contact problem. Measurements covered penetration depths from first detection of contact, where the strains are smallest and the material response should most likely be interpretable in terms of linear viscoelastic analysis, to much greater depths where the strains far exceed the yield values. The observations are tabulated, as are the values of parameters that allow the data to be modeled to within experimental error. These parameters fit into a specially developed empirical law designed to facilitate subsequent treatment of the data using Laplace transform methods. An analysis is offered to try to sort out time-dependent force relaxation from depth-dependent force increase during the progress of the penetration. The results of the response at small penetration depths are in broad accord with published relaxation moduli. However, the dependence of force upon indenter geometry does not follow simple expectation.     

Hardwood fibre fractionation using rotating cone

Rotating cones were used to carry out fibre fractionation of a 100% hardwood pulp having a consistency of 0.93± 0.02%. The unique features of the rotating cone fractionator adopted in this study were that its surface was constructed from a sieve mesh, thereby introducing a “rough” surface, and the feed pipe was located at an off-centre position to the axis of rotation. In all earlier studies reported in the literature, the fibre fractions were collected at different radial locations. However, in the present study, collection of the various fractions was made either at different radial or at angular positions. Tests were conducted for 120 mm diameter cones having a cone angle of 30°. Visual observations, photographs and fibre length measurements suggested that fibre fractionation performance strongly depended on the flow characteristics formed on and surrounding the rotating cone. In turn, they were found to be strongly dependent on the surface roughness, rotational speed and feed flow rate. Results for fibre fractionation showed quite conclusively that rotating cones made from 20-mesh and 32-mesh screens were more effective for fibre fractionation than “smooth” surface rotating cones.